1. Field of the Invention
This invention relates to a gaming machine, such as a slot machine, and a pachinko game machine, as well as a ball-shooting game machine, which is provided with a variable display block for variably displaying a plurality of symbols thereon.
2. Prior Art
In a slot machine, for example, there is employed as the variable display block, a display mechanism of a rotation reel type, in which reels each having a plurality of symbols arranged on its peripheral surface are driven for rotation by drive means, such as a stepping motor. During the game, a win or a lose is determined depending on combinations of symbols positioned along predetermined win lines when the reels are stopped, and if a play of the game results in a win, a number of coins or medals corresponding to a kind of the win is paid out.
In gaming machines adapted to vary a display of symbols in a plurality of columns as described above, the variable display of symbols is controlled by a control system comprised of a microcomputer so as to prevent a probability of winning plays from being dependent on player's skill.
More particularly, in the case of a slot machine, when the player operates a lever or a start button, the control system drives the reels of the variable display block for rotation, and at the same time samples a random number. Then, the control system determines whether or not the sampled random number corresponds to a win with reference to a predetermined winning condition table, and based on results of the determination, symbols (stop symbols) are determined which should be displayed within a viewing window through which the symbols are visible when the reels are stopped, followed by stopping the rotation of the reels after a predetermined time period.
In a ball-shooting game machine, such as a pachinko game machine, neither the lever nor the start button is operated, but upon entry of a shot game ball into a win area called a "start hole", a control system starts to operate a variable display block and at the same time samples a random number. The control system makes a determination based on the random number with reference to a winning condition table whether or not the present play is a win or a lose, whereby the stop symbols are determined, followed by stopping the variable display after a predetermined time period.
Further, in the case of a gaming machine provided with a variable display block of a video type, e.g. formed by a CRT (Cathode Ray Tube), graphics data corresponding to symbol patterns is stored in a memory device (symbol ROM) in a predetermined order, and a control system reads data of symbols patterns to be displayed on the variable display block from the symbol ROM.
In any case, in gaming machines provided with a variable display block, movement of a plurality of symbol columns is controlled by a microcomputer or the like, for stop thereof at a predetermined position.
As described above, in conventional slot machines, the control system causes all the reels to start rotation and enter the state of uniform rotation, and then after a predetermined time period, controls the stop of the rotation of the reels such that stop symbols are displayed, which are determined based on a prior win determination. During this stop control, however, the reels are not stopped at equal time intervals. This is because the stop symbols to be lined up along a win line are positioned on different locations or levels on respective reels, and hence it is required to correct the timing of the deceleration and stopping process in order to line up the stop symbols on the win line. That is, the time intervals of the process of stopping the respective reels requires different time durations for each such reel. For example, assuming that three reels start to be rotated simultaneously, and then a first reel, a second reel, and a third reel are automatically and sequentially stopped in the right-to-left order as mentioned, a time interval from the stopping of the first reel to the stopping of the second reel can be significantly different from a time interval from the stop of the second reel to the stop of the third reel.
In this way, since the timing of stop the stopping of each reel bearing an endless symbol column is irregular, a player can feel that the stop symbols are lined up along the win line not by chance depending on timing of a pull of the lever, but by intentional control by the slot machine, which can make him uninterested in the game. This disadvantageous characteristic inconvenience can become with a type of the slot machine which is not provided with reel stop buttons, but adapted to stop the reels after a predetermined time period. Further, in the case of a ball-shooting game machine as well, irregularity of time intervals of stop of symbol columns of the variable display block can cause the same loss of interest in the game.
In particular, in these gaming machines, whether a play is a win or a lose is known only when all the symbol columns are stopped, and hence the player watch for stopping of the symbol columns with much interest. If, in spite of such keen interest of players in this moment, timing of stop of the symbol columns is irregular, the players can lose interest in the game.